The present invention concerns a procedure and a means for correcting the transversal profile of a chip, fibre or equivalent mat formed on a conveyor belt, said chip mat being formed with the aid of one or several rolls, most appropriately rake rolls, provided above the conveyor belt, in which procedure the free space for the chip mat, between the last roll and the conveyor belt, is adjusted transversally to the conveyor belt.
In apparatus of this kind, e.g. chip board is manufactured. Chips are then fed to rolls rotating above the means, preferably rake rolls, of which the direction of rotation is the same as the conveyor belt's direction of travel. The thickness of the chip mat being produced is determined by the distance between the last rake roll and the conveyor belt. The distance is usually adjustable. A problem has arisen how to achieve a uniform enough profile of the chip mat. In the EP application No. 0162118 published Nov. 22, 1985, this problem is solved by placing a profile sensor at the ultimate end of the conveyor belt, which transmits information on any non-uniformities to the last roll, of which the side-by-side sections are separately adjustable in vertical direction. In this way, the profile can be regulated transversally to the chip mat. For instance, when the sensor observes a raised portion in the profile, it transmits the information to the machinery operating the sections of said rake roll, said apparatus lowering the roll section located at the respective point so that less chips can pass through at this point, thus producing a level profile. The regulation suggested in the above-identified EP application cited is in itself operable, but recently a need to design the means in a simpler manner has arisen, since this kind of rotating roll adjusted stripwise is cumbersome and costly to manufacture.
The object of the present invention is to provide a procedure and a means of the kind outlined above, for regulating the transversal profile, which are free of the drawback mentioned.